State Key Laboratory of Endocrine and Metabolic Diseases, Chinese PLA General Hospital , Beijing , China .
Endocr Res. 2014;39(2):66-72. doi: 10.3109/07435800.2013.828741. Epub 2013 Sep 25.
In addition to their hypotensive properties, angiotensin receptor blockers (ARBs) have been shown to exert clinical antidyslipidemic effects. The mechanism underlying these ARB lipid metabolic effects remains unclear. Some ARBs, for example, telmisartan, activate peroxisome proliferator-activated activated receptor-gamma (PPAR-gamma). We hypothesized that PPAR-gamma-activating ARBs might exert antidyslipidemic effects via PPAR-alpha. In this study, we assessed the effect of telmisartan on the expression of PPAR-alpha and lipoprotein lipase (LPL). PPAR-alpha expression was detected by reverse-transcription polymerase chain reaction and Western blot in HepG2 hepatocytes as well as differentiated C2C12 myocytes treated with increasing concentrations of telmisartan (0.1-10 μmol/L) for 48 h. Results showed that 1 μmol/L and 10 μmol/L telmisartan significantly increased the expression of PPAR-alpha mRNA and protein in HepG2 cells (p < 0.01). No effect was shown in differentiated C2C12 cells. Similarly, 1 µmol/L and 10 μmol/L telmisartan significantly increased the expression of LPL mRNA and protein in HepG2 cells (p < 0.01), and this increase was significantly (p < 0.01) inhibited by the PPAR-alpha-specific antagonist MK886. These results indicate that certain of the antidyslipidemic effects of telmisartan might be mediated via increased PPAR-alpha-dependent induction of LPL expression.
除了具有降低血压的特性外,血管紧张素受体阻滞剂 (ARB) 已被证明具有临床抗血脂异常作用。这些 ARB 脂质代谢作用的机制尚不清楚。例如,某些 ARB,如替米沙坦,可激活过氧化物酶体增殖物激活受体-γ (PPAR-γ)。我们假设,激活 PPAR-γ的 ARB 可能通过 PPAR-α 发挥抗血脂异常作用。在这项研究中,我们评估了替米沙坦对 PPAR-α 和脂蛋白脂肪酶 (LPL) 表达的影响。通过逆转录聚合酶链反应和 Western blot 检测 HepG2 肝细胞以及用不同浓度替米沙坦 (0.1-10 μmol/L) 处理 48 小时的分化 C2C12 肌细胞中 PPAR-α 的表达。结果表明,1 μmol/L 和 10 μmol/L 替米沙坦显著增加 HepG2 细胞中 PPAR-α mRNA 和蛋白的表达 (p < 0.01)。在分化的 C2C12 细胞中未显示出作用。同样,1 μmol/L 和 10 μmol/L 替米沙坦显著增加 HepG2 细胞中 LPL mRNA 和蛋白的表达 (p < 0.01),并且这种增加被 PPAR-α 特异性拮抗剂 MK886 显著抑制 (p < 0.01)。这些结果表明,替米沙坦的某些抗血脂异常作用可能是通过增加 PPAR-α 依赖性诱导 LPL 表达介导的。